Drill Bit Size Chart
Tools
Data 2026.07.13-audit.1
Checking connection

Shop chart · landscape print

Reference on paper.
Assumptions attached.

The print sheet favors readable nominal conversions over a wall of decorative graphics. Metric rows are shown every 0.5 mm; use the live chart for the full 0.1 mm comparison series.

DRILL BIT SIZE CHART · SHOP REFERENCE

Nominal diameter equivalence

DATA
2026.07.13-audit.1
UNITS
IN / MM
SCALE
NTS
REV
AUDIT.1

Number drills

#800.01350.343
#790.01450.368
#780.01600.406
#770.01800.457
#760.02000.508
#750.02100.533
#740.02250.571
#730.02400.610
#720.02500.635
#710.02600.660
#700.02800.711
#690.02920.742
#680.03100.787
#670.03200.813
#660.03300.838
#650.03500.889
#640.03600.914
#630.03700.940
#620.03800.965
#610.03900.991
#600.04001.016
#590.04101.041
#580.04201.067
#570.04301.092
#560.04651.181
#550.05201.321
#540.05501.397
#530.05951.511
#520.06351.613
#510.06701.702
#500.07001.778
#490.07301.854
#480.07601.930
#470.07851.994
#460.08102.057
#450.08202.083
#440.08602.184
#430.08902.261
#420.09352.375
#410.09602.438
#400.09802.489
#390.09952.527
#380.10152.578
#370.10402.642
#360.10652.705
#350.11002.794
#340.11102.819
#330.11302.870
#320.11602.946
#310.12003.048
#300.12853.264
#290.13603.454
#280.14053.569
#270.14403.658
#260.14703.734
#250.14953.797
#240.15203.861
#230.15403.912
#220.15703.988
#210.15904.039
#200.16104.089
#190.16604.216
#180.16954.305
#170.17304.394
#160.17704.496
#150.18004.572
#140.18204.623
#130.18504.699
#120.18904.801
#110.19104.851
#100.19354.915
#90.19604.978
#80.19905.055
#70.20105.105
#60.20405.182
#50.20555.220
#40.20905.309
#30.21305.410
#20.22105.613
#10.22805.791

Letter drills

A0.23405.944
B0.23806.045
C0.24206.147
D0.24606.248
E0.25006.350
F0.25706.528
G0.26106.629
H0.26606.756
I0.27206.909
J0.27707.036
K0.28107.137
L0.29007.366
M0.29507.493
N0.30207.671
O0.31608.026
P0.32308.204
Q0.33208.433
R0.33908.611
S0.34808.839
T0.35809.093
U0.36809.347
V0.37709.576
W0.38609.804
X0.397010.084
Y0.404010.262
Z0.413010.490

Fractional drills

1/640.01560.397
1/320.03130.794
3/640.04691.191
1/160.06251.587
5/640.07811.984
3/320.09382.381
7/640.10942.778
1/80.12503.175
9/640.14063.572
5/320.15633.969
11/640.17194.366
3/160.18754.762
13/640.20315.159
7/320.21885.556
15/640.23445.953
1/40.25006.350
17/640.26566.747
9/320.28137.144
19/640.29697.541
5/160.31257.938
21/640.32818.334
11/320.34388.731
23/640.35949.128
3/80.37509.525
25/640.39069.922
13/320.406310.319
27/640.421910.716
7/160.437511.112
29/640.453111.509
15/320.468811.906
31/640.484412.303
1/20.500012.700
33/640.515613.097
17/320.531313.494
35/640.546913.891
9/160.562514.287
37/640.578114.684
19/320.593815.081
39/640.609415.478
5/80.625015.875
41/640.640616.272
21/320.656316.669
43/640.671917.066
11/160.687517.462
45/640.703117.859
23/320.718818.256
47/640.734418.653
3/40.750019.050
49/640.765619.447
25/320.781319.844
51/640.796920.241
13/160.812520.637
53/640.828121.034
27/320.843821.431
55/640.859421.828
7/80.875022.225
57/640.890622.622
29/320.906323.019
59/640.921923.416
15/160.937523.813
61/640.953124.209
31/320.968824.606
63/640.984425.003
11.000025.400

Metric · 0.5 mm steps

0.5 mm0.01970.5
1 mm0.03941.0
1.5 mm0.05911.5
2 mm0.07872.0
2.5 mm0.09842.5
3 mm0.11813.0
3.5 mm0.13783.5
4 mm0.15754.0
4.5 mm0.17724.5
5 mm0.19695.0
5.5 mm0.21655.5
6 mm0.23626.0
6.5 mm0.25596.5
7 mm0.27567.0
7.5 mm0.29537.5
8 mm0.31508.0
8.5 mm0.33468.5
9 mm0.35439.0
9.5 mm0.37409.5
10 mm0.393710.0
10.5 mm0.413410.5
11 mm0.433111.0
11.5 mm0.452811.5
12 mm0.472412.0
12.5 mm0.492112.5
13 mm0.511813.0

Audited cutting-tap subset

Manufacturer-published 65% / 75% rows

Discrete chart rows; calculated nominal percentage shown for transparency.

#1-64 UNC #53 0.0595 in 66.5% calc.
#6-32 UNC #36 0.1065 in 77.6% calc.
#10-24 UNC #25 0.1495 in 74.8% calc.
1/4-20 UNC #7 0.2010 in 75.4% calc.
5/16-18 UNC F 0.2570 in 76.9% calc.
3/8-16 UNC 5/16 0.3125 in 77.0% calc.
7/16-14 UNC U 0.3680 in 74.9% calc.
1/2-13 UNC 27/64 0.4219 in 78.2% calc.
#1-72 UNF #53 0.0595 in 74.8% calc.
#6-40 UNF #33 0.1130 in 77.0% calc.
#8-36 UNF #29 0.1360 in 77.6% calc.
#10-32 UNF #21 0.1590 in 76.4% calc.
5/16-24 UNF I 0.2720 in 74.8% calc.
9/16-18 UNF 33/64 0.5156 in 65.0% calc.
5/8-18 UNF 37/64 0.5781 in 65.0% calc.
7/8-14 UNF 13/16 0.8125 in 67.4% calc.
M1.6 × 0.35 1.25 mm 0.0492 in 77.0% calc.
M2 × 0.4 1.6 mm 0.0630 in 77.0% calc.
M3 × 0.5 2.5 mm 0.0984 in 77.0% calc.
M3.5 × 0.6 2.9 mm 0.1142 in 77.0% calc.
M4 × 0.7 3.3 mm 0.1299 in 77.0% calc.
M5 × 0.8 4.2 mm 0.1654 in 77.0% calc.
M6 × 1 5 mm 0.1969 in 77.0% calc.
M10 × 1.5 8.5 mm 0.3346 in 77.0% calc.
M14 × 2 12 mm 0.4724 in 77.0% calc.
M16 × 2 14 mm 0.5512 in 77.0% calc.
M18 × 2.5 15.5 mm 0.6102 in 77.0% calc.
M20 × 2.5 17.5 mm 0.6890 in 77.0% calc.
M22 × 2.5 19.5 mm 0.7677 in 77.0% calc.